Draft gear



July 5, 1932. w, COTTON 1,865,838

DRAFT GEAR Filed Dec. 15, 1924 2 Sheets-Sheet l ln enaanj/aZfer/Y w. H. COTTON July 5, 1932.

DRAFT GEAR 2 Sheets-Shet 2 Filed Dec. 15, 1924 Z w 5 c y M a uv a W.

Patented July 5, 1932 TES UNE'TED WALTER H. COTTON, OF CHICAGO, ILLINOIS, ASSIGNOR TO UNION DRAFT GEAR COM- PANY, OF CHICAGO, ILLINOIS, A CORPORATION OF DELAWARE DRAFT GEAR Application filed. December 15, 1924. Serial No. 755,844.

This invention relates to draft gears, and more particularly to the type in which intercalated friction plates are employed.

One of the objects of the invention is the provision of new and improved means for retaining the plates in assembled relation and for resisting lateral movement of said plates.

Another object of the invention is the provision of new and improved means and arrangement thereof for releasing the wedges aftercompression.

A further object of the invention is the provision of new and improved means for adjusting the lateral pressure on the friction plates for compensating for wear, looseness of parts and the like.

Other objects of the invention are the provision of a new and improved draft gear that is comparatively light in weight, cheap to manufacture, easily assembled, efficient in operation, composed of few moving parts, and that is simple and rugged in construction.

Other and further obj ects'and advantages of the invention will appear from the following description taken in connection with the accompanying drawings, in which Fig.1 is a plan view of a portion of the center sills of a railway car showing the invention in position therein, the gear being shown in horizontal section;

Fig. 2 is a section on line. 22 of Fig. 1;

Fig. 3 is a section on line 3-3 of Fig. 1;

Fig. 4 is a plan view of a portion of the center sills showing the invention in position therein, with parts in section and parts broken away;

Fig. 5 is a side elevation of the wedge; Fig. 6 is a similar view of the friction shoe; and r Fig. 7 is a perspective view of one of the friction plates.

On the drawings the reference character 8 designates the center sills of a railway car,

1 on which are mounted the draft lugs 9 and the buffer lugs 10. The coupler butt isshown at 11 and the coupler yoke at 12. A pair of follower plates 13 and 14 are adapted to engage the lugs 9 and 10. Mounted in the yoke 12 between the follower plates 13 and 14 and adapted to be engaged thereby are a plurality of intercalated friction plates overlapping at their inner ends. In the form of the device shown on the drawings two groups of plates are employed, one at each side of the gear. Each group comprises two sets of plates, one set of plates 15 being adapted to be engaged by the follower plate 13 and the other set 16 being adapted to be engaged by the follower plate 14.

2 Suitable means are provided for adjustably holding the plates inassembled relation and limiting the outward lateral movement of the same. As shown, each set of plates is provided with an elongated opening 17 at one end and with a slot 18 at the other end. Retracting bars 19 and 20 are adapted to engage the elongated openings 17 in the two sets of plates, respectively. The elongatedopenings will permit a slight relative movement of the retracting bars and plates. The plates 15 are mounted on the retracting bar 19 and when in position in the gear the slot 18 thereof is adapted to engage the opposite retracting bar 20 for holding the same'in proper position. The plates 16 are similarly mounted onthe retracting bar 20 and their slotted ends are adapted to engage the opposite bar 19. Suitable plate retaining members 21 are adjustably mounted on each end of the retracting bars for engaging the outer sides of the two groups of friction plates to limit their lateral movement. These plates may be secured to the bars 19 and 20 in any suitable manner,as by being screwed thereon, cotter pins 22 being employed for preventing accidental removal of said plates. If for any reason it becomes necessary or desirable to adjust the lateral pressure on the plates, as when they become so worn that sufficient pressure is not developed during compression, the plates may be adjusted by screwing the same on one or both of the retracting bars the desired amount.

Means are provided for forcing the plates laterally outwardly for creating friction between the same during the compression of the gear. A pair of friction shoes 23 and cooperating wedge members 28 at each end of the gear are employed for this purpose. Each shoe is provided with an opening 24 through which the retracting bars 20 are adapted to extend. This opening is sufliciently large to permit the retracting bars to be readily inserted without permitting relative movements of the parts during the operation of the device. Each shoe has outwardly extending flanges 25 which are adapted to engage the edges of the friction plates for holding the shoes and plates in alinement. The shoes are also provided with inclined surfaces 26 which are adapted to be engaged by corresponding in clined surfaces 27 of the wedge members 28. The wedge members 28, one of which is employed at each end of the gear, are slotted at their inner ends as at 29 for receiving the retracting bars 20 and permitting a relative movement of the wedges and bars.

Suitable resilient means, such as the coil springs 31, are employed for releasing the wedge members 28 after the compression of the gear has been relieved. The wedge members are preferably provided with spring seats 32 within which the ends of the springs 31 are adapted to engage. These springs are preferably, though not necessarily, arranged one above the other. Means are provided for resiliently resisting the inward movement of the shoes during compression of the gear and for moving the friction shoes and friction plates outwardly to normal position after the wedges have been released. As shown, springs 33 are employed for this purpose. These springs, of which there are preferably though not necessarily two in number, are adapted to engage the retracting bars to resist inward movement of the same. Recesses 34 are provided in the shoes for receiving the ends of the springs for retaining the same on the bars 19 and 20.

In the normal position of the gear the outer ends of the wedge members 28 extend beyond the plane of the friction plates 15 and 16, whereby, when the gear is compressed, the follower plates 13 and 14: will engage the ends of said wedges before coming in contact with the plates. On the release the springs force the wedges outwardly to release the transverse pressure on the plates. In order that the parts he returned to normal position after compression it is necessary that both wedges be released. In order to insure the release of both wedge members suitable means are provided for limiting the outward movement of the wedges relatively to the retraction of the plates. In the present invention this .i s accomplished by providing an interlocking connection between the wedges and the shoes whereby the wedges will have a limited rearward movement relative to the shoes. The wedges are provided with lugs 35 which are adapted to extend between lugs 36 and the flanges 25 on the shoes. During compression of the gear the wedges may move for ardly relatively to the shoes and on release the wedges are free to move rearwardly until the lugs 35 and 36 engage. Should one of the wedges become stuck temporarily the other wedge will move outwardly into engagement with the lug 36 after which the full force of the springs 31 will be exerted to release the other wedge.

In the operation of the device, the bufiing stress forces the wedges inward against the shoes and springs for. compressing the plates. The slots in the plates permit the retracting bars and shoes to be moved inwardly slightly independently of the plates thus slightly permitting the wedges to move inward far enough to cause the follower bars to engage the ends of the plates and compress the same. After compression the wedges are forced outward by the springs 31 causing the lugs 35 thereon to engage the lugs 36 on the shoes, thereby insuring the release of both wedges. The release of the wedges will relieve the transverse pressure on the shoes, whereupon the springs 33 will tend to force the retracting bars, shoes and plates, outwardly to normal position. By reason of the engagement of the lugs 35 and 36 the springs 31 will assist in returning these parts to normal position.

It is thought from the foregoing taken in connection with the accompanying drawings, that the construction and operation of my device will be apparent to those skilled in the art, and that various changes in size, shape, proportion and details of construction may be made without departing from the spirit and scope of the appended claims.

I claim as my inventon:

1. In combination, two groups of intercalated friction plates, means for creating transverse pressure on said plates during compression, said means including retracting bars extending through said plates, plate retaining members on the ends of said bars in frictional. engagement with said group of plates, means for preventing the disengagement of said plates and bars, said last-named means at one side of said gear being connected to the corresponding means at the other side thereof, solely by said bars, and resilient means between said groups for returning the parts to normal position after compression.

2. In a draft gear, a group of intercalated friction plates, means for creating lateral pressure on said plates during compression of said gear, said means including retracting bars extending through said plates, means attached to the ends of said bars for resisting lateral movement of said plates, said lastnamed means and bars being movable together during the entire operation of said gear, and resilient means for restoring the parts to normal position after compression.

3. In a draft gear, a group of intercalated friction plates, means including wedge and shoe members at each end of said gear for creating lateral pressure transversely outwardly on said group of plates, resilient means for resisting the inward movement of said shoe and wedge members and for returning the parts to normal position after compression, and an interlocking loose motion connection between said shoes and wedges for limiting their relative movement longitudinally of the gear, said connection being independent of the wedging faces of the wedges.

4. In a draft gear, two groups of intercalated friction plates, means including wedges and shoes between said groups at each end thereof for creating lateral pressure transversely outwardly on said plates during compression of said gear, retracting bars engaging said plates and shoes and movable therewith, resilient means between said bars and engaging the same, springs for resisting the inward movement of said wedges, and an interlocking loose motion connection between said shoes and wedges for limiting their relative movement longitudinally of the gear.

5. In combination, a pair of center sills having draft and buffer lugs thereon, a pair of follower plates for engaging said lugs, a pair of groups of friction plates between said followers, a plurality of friction shoes for engaging the innermost of said friction plates, a pair of wedge members for forcing said shoes laterally into frictional engagement with said friction plates, and means including members extending through said plates and having plate engaging elements attached to the ends thereof, for engaging the sides of said plates, for limiting said lateral movement of said friction plates.

6. In a draft gear, a group of intercalated plates, wedge means at each end of the. gear to force said plates laterally during compression into frictional engagement with each other, said means including retracting bars extending transversely through the longitudinal aXis of the gear, means threaded on the ends of said bars for limiting the lateral movement of said plates, and means to restore the parts to normal position after compression.

7. In combination, sills having draft and buffer lugs thereon, follower bars for engaging said lugs, a pair of groups of intercalated plates between said bars, each group comprising two sets of plates, wedging means between said groups and engaging said follower bars, a retracting bar extending through each set of plates and the corresponding wedging means, plate retaining members fixed to the outer ends of said retracting bars for limiting the lateral movement of said plates, and resilient means for restoring said parts to nor mal position after compression.

8. In a draft gear, a group of intercalated friction plates, a follower at each end of said group of plates, friction shoe members for forcing said platesinto frictionalengagement with each. other, wedge members for engaging said shoes, means for limiting the lateral movement of said plates, an interlocking connection between one set of said members and said means, interengaging means on said members for limiting the outward movement of said wedge members relative to said shoe members, and resilient means for restoring the parts to normal position after compression.

9. In a draft gear, a group of intercalated friction plates, means at each end of said gear for creating transverse pressure on said plates during compression of said gear, and means extending laterally from said gear and adjustable from the exterior thereof for adjustably limiting the lateral movement of said plates.

10. In a draft gear, a group of intercalated plates, retracting bars therefor, means including wedge and shoe elements for creating transverse pressure on said plates, resilient means for releasing said wedge elements after compression, spring means for resisting the inward movement of said shoes and interengaging lugs on said elements whereby said spring and resilient means will cooperate to return the bars to normal position after compression.

11. In a friction shock absorbing mechanism, the combination with front and rear follower acting means; of a spring resistance interposed between said followers; a column load-sustaining means interposed between said followers, said last named means consisting of a plurality of groups of relatively movable intercalated friction plates; lateral pressure creating means between saidgroups of plates at each end of the gear co-operating with said plates at each side of said gear and adapted to be actuated upon relative movement of said followers, and adjustable abutment means engaging said groups of plates on the outer sides thereof for limiting the lateral outward movement of said plates.

12. In a friction shock absorbing mechanism, the combination with front and rear follower-acting means; of a plurality of longitudinally arranged, intercalated friction plates interposed between said means and adapted to be moved relatively to each other upon relative movement of said follower acting means, said plates being of such a length that the opposite ends of each plate will abut with the front and rear follower acting means, respectively, when the gear is fully compressed; a. lateral, wedge-pressure creating means comprising wedge blocks and cooperating wedge shoes interposed between said first named means co-operating with said plates; and a spring resistance co-acting with said wedge pressure-creating means, and a loose motion connection among said wedge-pressure creating means, said connection being independent of the wedging faces of said blocks and shoes.

13. In a friction shock absorbing mechanism the combination with front and rear relatively movable follower elements having lateral wedge pressure means movable therewith; a plurality of relatively, longitudinally movable interca-lated friction plates intel-posed between said follower elements and adapted to be engaged and moved thereby upon relative approach of the same; wedge friction elements interposed between the wedge means and said plates at each end of the gear; spring resistance means; spring followers co-operating with the wedge friction elements at the front and rear ends of the mechanism, means including retracting bars for returning the parts to normal position after release, and means adjustably connected to the ends of said bars for adjustably limiting the lateral movement of the plates In testimony whereof I affix my signature.

lVALTER H. COTTON. 

